# Conduction Convection Radiation Worksheet Bibb

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```					Bibb County Public Schools                                                      Unit Plan
Energy
High School Physical Science

Unit Title: Energy                               Topic: Conservation of Energy
Designer: Carol Miller and Mickey Daniell        Grade Level: 9-12
Subject/Course: Physical Science                 Pacing: 6 days

SPS7. Students will relate transformations and flow of energy within a system.
a. Identify energy transformations within a system (e.g. lighting of a match).
b. Investigate molecular motion as it related to thermal energy changes in
terms of conduction, convection, and radiation.
c. Determine the heat capacity of a substance using mass, specific heat, and
temperature.
d. Explain the flow of energy in phase changes through the use of a phase
diagram.

Brief Summary of Unit:
The unit will define energy and address its five basic forms. The Law of Conservation of
energy will be discussed and demonstrated in practical lab applications, as well as, in class
and web based activities. Also, the relationship of temperature and heat will be addressed
while introducing students to the Principle of Thermodynamics.

Unpacked Standards

Big Ideas:
1. Law of Conservation of Energy
2. Energy is transformed from one form to another within a system.
3. How does energy flow and transform?
Enduring Understandings:
1. SWU that energy comes in two forms.
2. SWU that when energy transforms or flows, it is conserved.
3. SWU that within systems energy can be stored or will flow from an area of greater
energy concentration to lesser energy concentration.
Unit Essential Questions:
1. What is energy?
2. What is the difference between heat and temperature and what is their relationship to
thermal energy?
3. How does the kinetic energy within a substance determine the arrangement of
molecules in different phases of the substance?
4. How does energy flow affect weather patterns?
5. Is matter a necessary requirement for the transfer of energy? Does all matter transfer
energy equally?
6. If the Law of Conservation of Energy is true, how can we have an energy crisis?
7. How will mixing two materials at different temperatures demonstrate the flow of energy
between greater and lesser concentrations?
Reasoning:
 compare and contrast conduction, convection and radiation
 understand that energy is transformed not destroyed
 compare/contrast heat and temperature
 evaluate energy transformation in daily examples

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Bibb County Public Schools                                                  Unit Plan
Energy
High School Physical Science
Knowledge:
 Energy is the ability to do work.
 Five basic forms of energy (mechanical, heat, chemical, electromagnetic, nuclear).
 Energy transfer can occur through conduction, convection, and radiation.
 Energy in a system is conserved.
 Heat is the measure of thermal energy transferred between objects.
 Temperature is the average kinetic energy of a substance.
 Principles of Thermodynamics.

Skills:
      Calculate energy transfer using specific heat values.
      Construct and label energy map
      Construct and label a phase change diagram
      Compare/contrast heat and temperature
      Convert between Fahrenheit, Celsius, Kelvin temperature scales
      Convert between Joules and Calories
      Analyze graphs
      Basic algebra
      Use of a meter stick; balance; graduated cylinder; thermometer; stopwatch
      Recognize/identify uses of potential and kinetic energy
      Calculate energy (GPE, KE, ME); Joules Calories

Language:
Absorb, chemical energy, conduction, conductor, convection, energy, heat capacity, heat,
insulator,     kinetic energy, Law of Conservation of Energy, mechanical energy, nuclear
energy, phase diagram, energy, radiation, specific heat, system, temperature, thermal energy.

Evidence of Student Understanding

 Demonstrating Energy Transformation Activity - Demonstrates some common energy
transformations and learns ways to identify them.
 Concept Map Organizes - concept of thermal energy (Glencoe Physical Science page
185)
 Cheeto’s™ Lab CHEETO LAB.doc
 Ice Water Lab (optional Lab) - Shows the direction of flow of energy to explain why the
soda becomes cold.
 Heat transfer in Mixes Lab - Determine conservation of energy in terms of heat flow
by performing calorimetric with cold and hot water. Explain findings in a
comprehensive lab report
 Heat Transfer Lab Part II - How do temperature and Energy Relate? worksheets\How
Do Temperature and Energy Relate.doc
 Quizzes – vocabulary and problems

Other Evidence:
Work Energy Theorem Illustrations with interactive questions

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Bibb County Public Schools                                                 Unit Plan
Energy
High School Physical Science
http://www.physicsclassroom.com/Class/energy/u5l2a.html

PE and KE Illustrated pages with interactive questions
http://www.physicsclassroom.com/Class/energy/U5L1c.html

Online Problems:
 http://science.widener.edu/svb/tutorial/waterheatcsn7.html
 http://science.widener.edu/svb/tutorial/heatxfer1csn7.html
 http://science.widener.edu/svb/tutorial/heatxfer1wpcsn7.html
 http://science.widener.edu/svb/tutorial/heatxfer2csn7.html

Plan for Learning Experiences and Instruction

1                    2                     3                  4                    5
Introduce five       Law of                Temperature and    Lab: Heat Transfer   Quiz
Forms of Energy      Conservation of       Heat               in Mixes part I
http://www.howe.k1   Energy
ps/penergy.htm       Types of forces of    conduction,
friction and effect   convection,        Lab Heat Transfer    Cheetos Lab
KE and PE            on law of             radiation          Part II
Interactive          conservation of                          How do
websites             energy / PE and       Demo: Convection   temperature and
http://www.physics   KE.                   currents           Energy relate
classroom.com/Cla    Internet activity:                       Homework             Review Online
ss/energy/U5L1c.ht   Roller coaster        Heat Problems                           Problems
ml                   demos and Thrill                         Calculate Specific   for students with
Physics worksheet                        Heat                 home internet
Homework                                                                           access
Energy KE and PE     Demo: Work
Energy theorem
6
Review Unit 2

Test Unit 2
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Bibb County Public Schools                                                         Unit Plan
Energy
High School Physical Science

Activities (list and explain each – include more specific directions as attachments)

Visit this site http://www.howe.k12.ok.us/~jimaskew/ps/penergy.htm and complete assignment
271 on day 1 and Concept Understanding on Day 2.

Energy: KE and PE calculations worksheet worksheets\pss - energy (ke and pe).doc

Demo: Convection currents worksheets\Colorful Convection Currents.doc

Heat Problems (Q = m c ∆ T) worksheets\Heat worksheet.doc

Roller coaster demos and Thrill Physics worksheet
 http://www.funderstanding.com/k12/coaster/ Students adjust settings using slider
controls for the height of hill #1, hill #2, the size of a loop, the initial speed of the
coaster, its mass, the gravity at work and the amount of friction on the track.
 http://www.learner.org/exhibits/parkphysics/coaster/ This simulation has students
select from choices for different elements: height of hills, shape of hills, loop shape,
and exit path. Students get feedback about safety and fun level of the coaster.
 http://dsc.discovery.com/convergence/coasters/interactive/interactive.html Students
select from design elements and sequence them into a ride before submitting it to
Vince, who will critique the ride for level of fun.

Specific Heat calculations worksheet (heat lost = heat gained) worksheets\ps - heat
problems.doc

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Bibb County Public Schools                                                     Unit Plan
Energy
High School Physical Science

#19 – Heat Transfer in Mixes: Part I

Discussion: If you mix a bucket of cold water with a bucket of hot water, the temperature of
the mixture will be between the two initial temperatures. What information would you need to
predict the final temperature? This lab investigates what factors are involved in changes of
temperature. Answer the ―Situation‖ questions at the top of your lab sheet before going
further.

Objective: To predict the final temperatures when different volumes of water at different
temperatures are mixed.

Materials:
2 beakers                                    1 large Styrofoam cup
2 thermometers                               hot plate
2 small Styrofoam cups

Procedure – Part I:
1. Measure out 200 mL of tap water into one of the beakers. Use a thermometer to
measure and record the temperature of the tap water.
2. Use the second beaker to heat 200 mL of water on the hot plate. Use the hot plate
setting recommended by the instructor.
3. Check the temperature of the heating water by holding a thermometer with the bulb in
the middle of the water. DO NOT let the thermometer sit in the beaker with the bulb on
the bottom as this will cause your thermometer to BREAK!
4. When the hot water has reached 60 degrees Celsius use your beaker tongs to remove
it from the hot plate. Turn the hot plate off and unplug it. Record the temperature of
the hot water.
5. Predict what your new temperature would be if you mixed the two and record this
6. Mix the two volumes of water in the large Styrofoam cup and stir with the stirring rod.
7. Observe the temperature for about a minute after stirring and record the highest
temperature you observed.
8. Answer the ―Analysis‖ questions under the data table before going further.

Procedure – Part II:
9. Measure out 100 mL of tap water into one of the beakers. Use a thermometer to
measure and record the temperature of the tap water.
10. Use the second beaker to heat 200 mL of water on the hot plate. Use the hot plate
setting recommended by the instructor.
11. Repeat steps 3-8.

Procedure – Part III:
12. Measure out 200 mL of tap water into one of the beakers. Use a thermometer to
measure and record the temperature of the tap water.
13. Use the second beaker to heat 100 mL of water on the hot plate. Use the hot plate
setting recommended by the instructor.
14. Repeat steps 3-8.

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Bibb County Public Schools                                                       Unit Plan
Energy
High School Physical Science

#19 – Heat Transfer in Mixes: Part I

Situation: Imagine a small cup of 60 degree Celsius water and large bucket of 20 degree
Celsius water.
1. Which is hotter 0 the cup or the pail? Why?
2. Which do you think has more thermal energy? Why?
3. Which would take longer to change its temperature by 10 degrees if the cup and pail
were set outside on a cold day? Why?
4. If you put the same amounts of red-hot iron into the cup and into the pail, which one
would change temperature more? Why?

Procedure – Part I
Temp of Tap Water        Temp of Hot Water       Prediction                      Actual
(degrees Celsius)       (degrees Celsius)  Mixture Temperature           Mixture Temperature
(degrees Celsius)            (degrees Celsius)

Analysis:
2. If there is a difference, why do you think your prediction was different than the actual
temperature?

Procedure – Part II
Temp of Tap Water        Temp of Hot Water       Prediction                      Actual
(degrees Celsius)       (degrees Celsius)  Mixture Temperature           Mixture Temperature
(degrees Celsius)            (degrees Celsius)

Analysis:
3. Is there a difference between your prediction and your observation? Why?
4. Which of the water samples (tap or hot) changed more when it became part of the
mixture? Why do you think this happened?

Procedure – Part III
Temp of Tap Water        Temp of Hot Water       Prediction                      Actual
(degrees Celsius)       (degrees Celsius) Mixture Temperature            Mixture Temperature
(degrees Celsius)             (degrees Celsius)

Analysis:
5. Is there a difference between your prediction and your observation? Why?

6
Bibb County Public Schools                                                Unit Plan
Energy
High School Physical Science
6. Which of the water samples (tap or hot) changed more when it became part of the
mixture? Why do you think this happened?

7
Bibb County Public Schools                                                  Unit Plan
Energy
High School Physical Science
#20 - Heat Transfer in Mixes – Part II

Discussion
If you throw a hot rock into a pail of cool water,
you know that the temperature of the rock will go down.
You also know that the temperature of the water will go
up—but will its rise in temperature be more than, less
than, or the same as the temperature drop of the rock?
Will the temperature of the water go up as much as the
temperature of the rock goes down? Will the changes of
temperature instead depend on how much rock and
how much water are present and how much energy is
needed to change the temperature of water and rock by
the same amount?
You are going to study what happens to the
temperature of water when hot nails are added to it.
Before doing this activity, think about the following
questions.

1. Suppose that equal masses of water and iron are at the same temperature.
Suppose you then add the same amount of heat to each of them. Would one change
temperature more than the other?
YES || NO (circle one)
If you circled "yes," which one would warm more?
WATER || IRON (circle one)
2. Again, suppose that equal masses of water and iron are at the same temperature.
Suppose you then take the same amount of heat away from each of them. Would one
cool more than the other?
YES || NO (circle one)
If you circled "yes," which one would cool more?
WATER || IRON (circle one)

7. Suppose you have equal masses of water and nails at the same temperature.
Suppose you then light similar candles and place a candle under each of the masses,
letting the candies burn for equal times. Would one of the materials change
temperature more than the other?
YES || NO (circle one)
If your answer to me question is "yes," which one would reach a higher temperature?

8. Suppose you have cold feet when you go to bed, and you want something to warm
your feet. Would you prefer to have a hot-water bottle filled with hot water, or one filled
with an equal mass of nails at the same temperature as the water? Explain your
choice.
WATER || NAILS (circle one)

8
Bibb County Public Schools                                               Unit Plan
Energy
High School Physical Science
9. Why does tie climate of a mid-ocean island stay nearly constant, getting neither very
hot nor very cold?

#20 - Heat Transfer in Mixes – Part II

temperature
Step 4             of cold water

temperature
Step 4             of hot water

Step 4: Is the
temperature of the hot
water equal to the
temperature of the nails?

Step 4: Why do you
think it is or is not?

Step 4: What would be
an alternate method to
heat the nails to a known
temperature?

predicted
Step 5             temperature
of mixture 
actual
Step 6             temperature
of mixture 

Step 6: How close is
observed value?

temperature
Step 8             of hot water

temperature
Step 9             of cold water

9
Bibb County Public Schools               Unit Plan
Energy
High School Physical Science
predicted
Step 10           temperature
of mixture 
actual
Step 11           temperature
of mixture 

Step 11: How close is
observed value?

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Bibb County Public Schools                                           Unit Plan
Energy
High School Physical Science

#20 - Heat Transfer in Mixes – Part II

Purpose: To predict the final temperature of water and nails when mixed.

Materials:
   Harvard trip balance
   2 large insulated cups
   thermometer (Celsius)
   hot and cold water
   paper towels

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Bibb County Public Schools                                                                    Energy
Unit Plan
Physical Science
 bundle of short, stubby nails tied with string

Step 1: Place a large cup on each pan of the balance. Drop the bundle of nails into one of the
cups. Add cold water to the other cup until it balances the cup of nails. When the two cups are
balanced, the same mass is in each cup - a mass of nails in one, and an equal mass of water in
the other.
Step 2: Set the cup of cold water on your work table. Lift the bundle of nails out of its cup and
place it beside the cup of cold water.
Step 3; Fill the empty cup ¾ full with hot water. Lower the bundle of nails into the hot water and
leave it there for two minutes to allow the nails to come to the temperature of the hot water.
Step 4: Measure and record the temperature of the cold water and the temperature of the hot
water around the nails. Answer the three questions on your data table before going further.
Step 5: Predict and record what the temperature of the mixture will be when the hot nails are
Step 6: Lift the nails from the hot water and put them                                    quickly
into the cold water. When the temperature of the                                          mixture
before going further.
Step 7: Now you will repeat Steps 1 through 6 with hot                                    water and
cold nails. First, dry the bundle of nails with a paper                                   towel.
Then, balance a cup with the dry bundle of nails with a                                   cup of hot
water.
Step 8: Remove the nails and fill the cup ¾ full with                                     cold
water. Record the temperature of the hot water in the                                     first cup.
Step 9: Lower the bundle of nails into the cup of cold                                    water,
wait one minute (why?), and then record the
temperature of the water around the nails.
Step 10: Predict and record what the temperature of the mixture will be when the cold nails are
Step 11: Lift the nails from the cold water and put them quickly into the hot water. When the
temperature of the mixture stops changing, record it. Answer the questions on your data table
before going further.

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Bibb County Public Schools                                                                               Energy
Unit Plan
Physical Science
Colorful Convection Currents
Convection is one of those words that we often hear used, but we may not completely understand its
meaning. Weather forecasters show how convection currents are formed when warm and cold air masses
meet in the atmosphere. Convection currents are responsible for warm water currents that occur in oceans.
This activity demonstrates convection currents in a very colorful fashion.

Materials:
- Four empty identical bottles (mouth of the bottle should be at least 1 1/2 inches in diameter)
- Food coloring (yellow and blue)
- 3 x 5 inch index card or an old playing card

Experiment:
1. Fill two bottles with warm water from the tap and the other two bottles with cold water. Use food coloring
to color the warm water yellow and the cold water blue. Each bottle must be filled to the brim with water.

2. Hot over cold: Place the index card or old playing card over the mouth of one of the warm water bottles.
Hold the card in place as you turn the bottle upside down and rest it on top of one of the cold water bottles.
The bottles should be positioned so that they are mouth to mouth, and the card is separating the two
liquids.

3. Carefully slip the card out from in between the two bottles. Make sure that you are holding onto the top
bottle when you remove the card. Observe what happens to the colored liquids in the two bottles.

4. Cold over hot: Repeat steps 2 and 3, but this time place the bottle of cold water on top of the warm
water. Observe what happens.

How it works:
Hot air balloons rise because warm air is lighter than cold air. Similarly, warm water is lighter in weight or
less dense than cold water. When the bottle of warm water is placed on top of the cold water, the more
dense cold water stays in the bottom bottle and the less dense warm water is confined to the top bottle.

However, when the cold water bottle rests on top of the warm water, the less dense warm water rises to
the top bottle and the cold water sinks. The movement of warm and cold water inside the bottles is referred
to as the convection current. In our daily life, warm currents can occur in oceans, like the warm Gulf Stream
moving up north along the American Eastern Seaboard.

Convection currents in the atmosphere are responsible for the formation of thunderstorms as the warm and
cold air masses collide.

Although all of the attention is focused on bottles where the colored liquids are mixing, the other set of
warm and cold water bottles help to illustrate another important phenomena that occurs in the atmosphere
during the winter months. During daylight hours, the sun heats the surface of the earth and the layer of air
closest to the earth. This warm air rises and mixes with other atmospheric gases. When the sun goes
down, the less dense warm air high up in the atmosphere often blankets the colder air that rests closer to
the surface of the earth. Because the colder air is more dense than the warm air, the colder air is trapped
close to the earth and the atmospheric gases do not mix. This is commonly referred to as temperature
inversion.

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Bibb County Public Schools                                                                              Energy
Unit Plan
Physical Science
What are the results of temperature inversion? Air pollution is more noticeable during a temperature
inversion since pollutants such as car exhaust are trapped in the layer of cold air close to the earth. As a
result, state agencies in many parts of the country oxygenate automobile fuels during winter months with
additives like MTBE in an attempt to reduce the harmful effects of trapped pollution.

What are the results of temperature inversion? Air pollution is more noticeable during a temperature
inversion since pollutants such as car exhaust are trapped in the layer of cold air close to the earth. As a
result, state agencies in many parts of the country oxygenate automobile fuels during winter months with
additives like MTBE in an attempt to reduce the harmful effects of trapped pollution.

14
Bibb County Public Schools                                                                      Energy
Unit Plan
Physical Science
Heat worksheet
Name:______________________________

1. How many calories of heat are required to raise the temperature of 500 grams of water from 20.6oC
to 50.6oC?

2. What temperature change will 200 grams of water undergo when it absorbs 200 calories?

3. A quantity of water is heated from 50.5oC to 80.6oC by absorbing 250 calories. What is the mass of
the water?

4. What is the specific heat of 50 grams of lead that undergoes a 200oC temperature change while
absorbing 300 calories?

5. What will the final temperature be if 50 ml of water at 20oC absorbs 2,000 calories?

6. What temperature change will 100 grams of water undergo when it absorbs 200
calories?

15
Bibb County Public Schools                                                                           Energy
Unit Plan
Physical Science
Name _________________ Date ________
Heat

1. An iron pipe (c = 450 J/ kg oC) with a mass of 510 grams cools from 20oC to         10oC?

2. Calculate the energy (heat) lost when a .01 kg sample of aluminum
(c = 920 J/kg K) cools from 75o C to 25oC.

3. A .250 kg metal sample (c = 380 J/ kg oC) is heated to 59oC. It is put into .20 kg of water at 10oC.
What is the final temperature of the sample and water?

4. A .5 kg of water at 15 o C is placed into a calorimeter. A sample of zinc is .04 kg at 110oC is placed
in the water. The final temperature of the water and zinc is 15.o C. What is the specific heat of the
zinc?

5. A hot block of metal is put into 0.20 kg of water at a temperature of 20oC (initial temperature of the
water). The new temperature of the water is increased to be 23oC. Calculate the energy (heat)
gained by the water.

16
Bibb County Public Schools                                                                          Energy
Unit Plan
Physical Science
CHEETO LAB

Purpose:
The purpose of this lab is to calculate the amount of Calories in a Frito brand Cheeto.

Q(heat) = m(mass) x Cp x Δ T                        Cp of water = 1 cal / gram o C

Pre-lab Questions:
1. Define heat, temperature, thermal energy.
2. What is a combustion reaction?
3. Define conduction, convection, and radiation.

Useful information:
To determine the number of calories in food, small samples are placed in a calorimeter and burned. The
increase in temperature of the surrounding water is measured and the calories are determined from the
mass and the specific heat of the water. So, the heat lost by the Cheeto is the heat gained by the water.
Because the amount of calories in food is very large, food calories are actually kilocalories.

Materials:
Small Erlenmeyer flask (clean cans work well)       paper clip             wooden splint
Ring stand                                          duct tape              thermometer
Test tube clamp                                     water
Cheeto                                              balance

Procedure:
1. Review lab safety for flammables.
2. Straighten the paper clip on one end. Wrap a small piece of duct tape on the opposite end for
insulation. You now have a skewer. Mass the paper clip and duct tape.
3. Skewer the cheeto length wise. Record the mass of the cheeto and paper clip.
4. Measure the mass of the flask. Record
5. Add approximately 50 ml of water, remass. Record
6. Measure the temperature of the water. Record
7. Place the flask in the test tube clamp on the ring stand.
8. Light one end of the wooden splint, hold the paper clip by the insulated end and light the cheeto.
Immediately hold the burning cheeto under the flask as close as possible without smothering the
flame.
9. Once the cheeto has extinguished itself, measure the final temperature of the water (stir the water
slightly). Record.

Calculations:
1. Determine the mass of the water, cheeto, the residue and the mass of the cheeto consumed in the
reaction.
2. Determine the temperature change of the water.
3. Calculate the heat gained by the water and the heat lost by the cheeto.
4. Determine the heat lost by the cheeto per gram of cheeto.

Conclusions:

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Bibb County Public Schools                                                                  Energy
Unit Plan
Physical Science
1. What instrument was used to measure the mass? Which instrument is best used to measure the
volume of a liquid?

2. How does the experimental value for calories compare with the actual value? What are some of the
reasons for the differences?

3. What types of heat transfer were observed during the reaction?

4. How many calories does the manufacturer allow for each gram of cheeto?

5. Calculate the percent error for the calories of the cheeto.

Mass of Paper Clip                                          ______ grams

Mass of Paper Clip and Cheeto                               ______ grams

Mass of Flask and Water                                     ______ grams

Temperature of Water (initial)                              ______ o C

Temperature of Water (final)                                        ______ o C

Mass of the Residue and Clip                                        ______ grams

Mass of the Cheeto                                          ______ grams

Mass of the Cheeto burned                                   ______ grams

Mass of the Water                                           ______ grams

Δ T of Water                                                ______ o C

Q gained by the water                                               ______ calories

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Bibb County Public Schools                                                                             Energy
Unit Plan
Physical Science
How Do Temperature and Energy Relate?

Often the concepts of heart and temperature are thought to be the same, but they are not.

Perhaps the reason the two are usually and incorrectly thought to be the same is because as human
beings on Earth everyday experience leads us to notice that when you heat something up, say like putting
a pot of water on the stove, then the temperature of that something goes up. More heat, more temperature
- they must be the same, right? Turns out, though, this is not true.

Temperature is a number that is related to the average kinetic energy of the molecules of a substance. If
temperature is measured in Kelvin degrees, then this number is directly proportional to the average kinetic
energy of the molecules.

Heat is a measurement of the total energy in a substance. That total energy is made up of not only of the
kinetic energies of the molecules of the substance, but total energy is also made up of the potential
energies of the molecules.

So, temperature is not energy. It is, though, a number that relates to one type of energy possessed by the
molecules of a substance. Temperature directly relates to the kinetic energy of the molecules. The
molecules have another type of energy besides kinetic, however; they have potential energy, also.

Temperature can be measured in a variety of units. If you measure it in degrees Kelvin, then the
temperature value is directly proportional to the average kinetic energy of the molecules in the substance.
Notice we did not say that temperature is the kinetic energy. We said it is a number, if in degrees Kelvin, is
proportional to the average kinetic energies of the molecules; that is, if you double the Kelvin temperature
of a substance, you double the average kinetic energy of its molecules.

Materials:

400 ml Beaker          Tongs          Two pieces of 20 cm waxed dental floss
Thermometer            Clock          Hot plate
Two Styrofoam cups

Procedures:

1. Mass one washer. Record the mass in grams. Tie 10 washers on a piece of floss, and 30 on the
other piece of floss.
2. Fill a beaker two-thirds full of water, lower the washers into the beaker and heat on the hot plate.
3. Measure 50 ml of room temperature water and pour into each cup.
4. Use a thermometer to measure and record the temperature of the water in the cups (the
temperatures should be approximately the same).
5. When the water in the beaker has boiled for about three minutes, use the tongs to remove a set of
washers. Shake any excess back into the beaker and quickly place the washers into one of the
cups. Record the highest temperature reached.
6. Repeat step 5 for the remaining set of washers, placing them into the other Styrofoam cup.

Pre-Lab Discussion:
19
Bibb County Public Schools                                                                         Energy
Unit Plan
Physical Science
1. Why is there no such thing as cold?
2. What is the temperature for the freezing point of water in:
a. Celsius
b. Kelvin
c. Fahrenheit
3. A vanadium bolt gives up 1124 J of energy as its temperature drops 25 K. If the bolt’s mass is 93
grams, what is its specific heat, Cp?
4. Determine which has a higher temperature, and which has a higher amount of total kinetic energy:
a cup of boiling water or Lake Tobesofkee
5. The density of air is approximately 1.220 kg/m3. A Westside High School science room is
approximately 10m by 13m by 3m. The specific heat of air is 250 cal/ kg . Co. How many
Kilocalories of heat energy are needed to raise the temperature in the room from 15oC to 20oC?
6. Where does the Earth receive the majority of its energy? How is the energy transferred?

Analysis:

1. Which cup had the higher final temperature?
2. Both cups of water start at the same temperature, and both sets of washers started at 100oC. Why
did one cup reach a final higher temperature?
3. Using the density of water, determine the mass of the water in the cups.
4. Calculate the specific heat of the washer and determine the type of metal the washer is most likely
constructed.

Heat Lost = Heat Gained
M c ∆T (metal) = M c ∆ T (water)

Common Specific Heat Capacities
Metal                   Cp – J / g – K                        mass of washer _______g
Aluminum                .91                            T initial of cup w/ 10 washers______OC
Cast Iron               .46                            T initial of cup w/ 30 washers______OC
Copper                         .39                            T final of cup w/ 10 washers______OC
Iron                    .46                            T final of cup w/ 30 washers______OC
Lead                    .13                            ∆T of cup w/ 10 washers______OC
Magnesium               1.05                           ∆T of cup w/ 30 washers______OC
Nickel                  .54                            mass of water in either cup ______g
Silver                  .23
Steel                   .5
Tin                     .21
Titanium                .54
Zinc                    .39

20
Bibb County Public Schools                                                                       Energy
Unit Plan
Physical Science
Name ______________ Date ______________ Period _____
Energy
1. Ace raised a 12.0 N science book from a table 75 cm above the floor to a shelf, 2.15 m above the
floor. What was the change in potential energy?

2. A meteor with a mass of 785 kg strikes Earth at a speed, relative to Earth at 25 km/s. Find the
kinetic energy of the comet in joules.

3. A 2.0 kg text book is lifted from the floor to a shelf 2.10 m above the floor. What is its potential
energy relative to the floor? What is its PE relative to the head f a 1.65 m tall person?

4. A rifle can shoot a 4.20 g bullet at a speed of 965 m/s. Find the kinetic energy of the bullet?

5. Find the kinetic energy of an airplane traveling at a speed of 67 m/s. The mass of the airplane is
5.0 x 102 kg.

6. A weightlifter lifts a 90.0 kg barbell from a stand 0.90 m high and raises it to a height of 1.75 m.
What is the increase in the potential energy of the barbell?

7. How does the gravitational potential energy of a 550 g object, 20.0 m above the ground, compare
with that of a 350 g object, 30.0 m above the ground.

8. A 20 kg rock is on the edge of a 100 m cliff. What potential energy does the rock possess relative
to the base of the cliff?

9. If the kinetic energy in the rock, in the problem above, determine its speed as it strikes the ground?

10. A 50 kg gymnast swings off a bar at 20 m/s. What is the gymnast’s KE as she leaves the bar?

11. Pam, wearing a rocket pack, stands on frictionless ice. She has a mass of 40 kg and acquires a
speed of 62.0 m/s. What is her KE?

12. Find the KE of a bullet weighing 10 g if its velocity is 300 meters per second.

13. A baseball has a mass of 0.14 kg. If it is thrown with a velocity of 7.5 m/s, what is its KE?

14. What is the PE of a block which weighs 40 N, when lifted to a table 2.0 ft. high?

21

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